Rudder Stock dropped

[Pengze]

Dear Sirs,
Would appreciate to advise what are the probable causes that could affect the Rudder Stock to drop down a few centimetres from its original position ?
The Rudder is of the semi-balance type.
The ship had been operating for about 3 years.
Hereby extend my thanks for yr kind response.

[Big Pete]

I heard of one case with a new Japanese built car carrier, where the rudder and stock dropped and it was found that the ship had been built without a Pallister bearing!! Nothing to support the weight of the rudder at all.

Generally check out the condition of the Rudder bearings and the ship's framework below the Rudder.

Good Luck and let us know what you found.

Big Pete

[Pengze]

Dear Sir,
1.We are currently using the cylindrical roller bearing (23052 CC/W33) for the rudder carrier, any different with Pallister bearing ?
2.Would appreciate yr elaborate clarification about the framework below the Rudder ?
3.Our current jumping collar clearance is abt 10mm, is it okay ?

[JK]

Consult your blueprints. All of the information is in there, or should be.